1. Field of the Invention
The present invention relates to fermented type sausages and improved methods for preparing the same.
2. Prior Art
Fermented sausages such as cervelat, summer sausage, salami, thuringer and the like are seasoned meat sausages which rely upon the growth of various organisms for flavor development. A typical cervelat summer sausage can be prepared by mixing ground beef trimmings, pork and beef hearts, beef cheeks, tripe and stomachs and coarsely ground pork trimmings and back fat with a salt-cure mixture. The mixture is cured for two days at 2.2.degree. C.-3.6.degree. C. After regrinding, the mixture is vacuum stuffed into casings. The sausage after washing is held in a green room for 24 hours at 7.2.degree. C. and then smoked. This method is disclosed in Food Products Formulary, Vol. 1, Meats, Poultry, Fish, Shellfish, by S. L. Komarik et al. (Avi Publishing Co.) at page 33 et seq.
The original procedure for preparing these sausages relied upon various organisms which were indigenous to sausage ingredients which originated in individual sausage making establishments. This method of chance inoculation of organisms of unascertained types led to unpredictable flavor and texture.
Since the chemical and bacteriological changes within the meat emulsion affect proper aging, coloring and stabilizing of the meat, and since the aging and coloring are related to taste and appearance, control over these changes is required for uniform sausage. The chemical and bacteriological changes can be controlled by inoculating the sausage emulsion with a pure culture. The use of externally added culture is disclosed in U.S. Pat. No. 2,907,661 which teaches that the fermented type sausages can be prepared by inoculation with a pure lactic acid starter culture such as Pediococcus cerevisiae.
For example, frozen lactic acid starter culture may be used in processing thuringer, summer sausage, cervelat, Lebanon bologna, pork roll, pepperoni, hot bar sausage, and the like. High quality fresh or frozen beef trimmings, pork trimmings, pork fat and the like with low bacterial counts are coarse ground with the cure (NaNO.sub.2), salt and spices. The pure culture after thawing is added at a rate of from about 1 to about 4 grams per kilogram of meat at a point before the end of the chop to ensure uniform distribution of the culture throughout the meat. After stuffing the mix into casings, the product is heated at fermentation temperature for a period of time sufficient to develop the desired tang by fermentation (about 12-24 hours). The product is then smoked and dried as required. This method is disclosed in Food Products Formulary, ibid., at page 46 et seq.
While the use of a pure culture strain has decreased the variability of the fermented type sausage, fermentation, being a natural process, is still subject to variation. Organism distribution as well as growth rates in any one area of the sausage may vary thus varying the taste developed. The end point of growth is usually determined by time or measurement of pH. On an average, these methods may be acceptable but for individual batches fermentation may not have been completed or gone beyond the point desired. Also, the fermenting sausage must be held under controlled conditions in the factory for the 12 to 24 hours to effect the proper development of lactic acid for the tangy taste. The output of the factory can be increased if this fermentation time as well as its possible variability could be reduced.
In addition, the pure culture is shipped in one instance in the frozen form. Apart from requiring refrigerated shipping and handling, the frozen culture must be thawed and diluted in water before addition to the sausage batch. Also, the manufacturer emphasizes that the following are critical factors relating to the use of the culture:
(1) Fresh or frozen meats of high quality (low bacterial population) should be used to control fermentation;
(2) For best results, straight sodium nitrite should be used at a level of 0.078 grams per 100 kilograms of meat;
(3) At least 0.75 kilograms dextrose per 100 kilograms meat must be used for optimum bacteria growth; and
(4) The proper level of humidity is required to maintain the proper moisture balance for optimum lactic acid organism growth.
While some of these factors such as low bacterial counts and reduced sodium nitrite may be good sausage making steps, the addition of dextrose and the humidity control are steps peculiar to the use of the culture.
Acidification agents such as glucono deltalactone (GDL) have also been added to meat emulsions. GDL does not lower the pH while the emulsion is being made. In the presence of heat and moisture, GDL hydrolyzes to gluconic acid. GDL is also used to increase the speed of color formation in the emulsion. (See Meat Emulsions, R. Saffle, Advances in Food Research, 16 (1968), pp. 105-160 at page 152).